Pump



Dern 3o, 1947. H, E. ADAMS PUMP Original Filed May 25. 1939 5 Sheets-Sheet l Namo nonns,

H. E. ADAMS Dec. 30, 1947.

PUMP

5 Sheets-$het 2 Original Filed lay 25, 1939 H. E. ADAMS Dec. 3o, 1947.

PUMP

5 Sheets-Sheet 3 Original Filed May 25, 1939 Dec. 30, 1947. H, E, ADAMS Y 2,433,539

PUMP

Original Filed May 25, 1939 g5 Sheets-$15761;

Dec. 30, 1947. H. E. ADAMS 2,433,589

PUMP Y original Filed may 25,` 1939' 5 sheets-sheet 5 Q. @Maw .4o @9 1f A lig Patented Dec. 30, 194'! Harold E. Adam to Nash Engi Conn., a corp Original application May 21, 1943, Serial N0.

26 Claims. (C

formed of corr Another ob be accomplished under ary conditions. While vitceramic or pottery material having glazed surfaces as in terra cotta nishes, in certain instances, where strength of the pump elements may be sacriced.

In the use of al1 vitr 25 crushing and bre tors from flying occurs.

Although vitreou elements are desir ing properties, be

e predetermined presin accordance with the devised a construction eve the increment over t of pressure either assembly or through the ltaneously, in both locathe escape of excessive chamber it is necessary construction in both the box assembly, and these a novel-manner in the e present invention is lling box assembly, wherei neering Com oration of Connec ,755. Divided and thi 499,561

TENT

s, South Norwalk, Conn assignor pany, South Norwalk,

' ticut 25, 1939, Serial No. s application August in eiiicient construction might require the use of one vitreous member wiping against another vitreous member, for the control of heat developed by the friction of the parts whereby the resultant dangers from overheating are reduced to a minimum.

In a stuiing box assembl tion at hand, it is necessary to provide for quick repair and replacement of worn parts, and toward this end there is devised a novel arrangement of. the stuiiing box elements which promotes ease and dispatch in the assembly and disassembly.

In order to obtain a proper seal for preventing the escape of pressure from the interior of the pump casing, it is necessary to provide a sealing surface where undue pressures may cause injury to the pump, and in the present invention the properly controlled pressure is placed on the seal elements that cannot be altered during the life of the pump.

In the present invention there is another meritorious feature residing in the novel design of the pump and stufling box assembly that provides a high coeiiicient of heat transfer in at least one of the rubbing elements of the seal, and to dissi- Vpate and transfer the heat by a novel arrangement, to the liquid being pumped.

Owing to the novel design of the pump of the present invention, it was found necessary to devise a means of connection between the pump suction and the suction piping, which would transfer the piping strains to the metal casing, relieving themore fragile pump casing and yet providing a positive connection to the pump casing for the Iiow of the liquid. By the present invention, there is devised a construction utilizing an adapter pipe section having an easy and economical manner of joining the pipe line to the pump casing while the metal casing takes the strain.

Another feature sid Dump.

Another feature of the volves a. novel arrangement of the gland and follower elements of the stuiiing box assembly so as to control any seepage of corrosive liquids in a manner to avoid contact withvthe metal parts of the pump.

With the foregoing and other o it will be seen thatv there is devi bination, construction,

present invention inbjects in view, sed a novel comand arrangement of the y based on the inven- 3 parts of a. pump which is highly efficient in operation, thoroughly reliable for its proposed uses, and that is comparatively inexpensive to use and repair.

Although the construction and operation of the preferred form of the invention is illustrated and described, it will be understood that it is the intention to claim all reasonable variations of the invention that may be considered within the scope of the appended claims.

In the drawings wherein like characters of reference indicate like parts throughout the several views- Fig. 1 is a side elevation of the motor showing a pump in detailed vertical section constructed in accordance with the present invention;

Fig, 2 is al section taken substantially on the plane of line 2-2 of Fig. 1, thereby showing the pump housing in front elevation;

Fig. 3 is a sectiorr through the pump housing taken substantially on the plane of line 3 -3 of Fig. 1, showing the pump casing in front elevation and with the outer housing section removedr Fig. 4 is a section through the pump housing taken substantially on the plane of the line 4-4 of Fig. 1 and with the volute section of the pump casing removed, showing the impeller and inner portion of the pump chamber in elevation;

Fig. 5 is a section taken substantially on the plane of line 5-5 of Fig. 1;

Fig. 6 is a. vertical section taken substantially on the plane of line 6-6 of Fig. 1;

Fig. 1 is a section taken substantially on the plane of line 1-1 of Fig. 1;

Fig. 8 is a fragmentary section of the pump housing and casing taken substantially on the plane of line 8-3 of Fig. 2;

Fig. 9 is a detailed section through the pump housing and casing taken substantially on the plane of line 9-9 of Fig. 2;

Fig. 10 is a fragmentary elevation partly in section of the inner housing section showing the rubber headed clamping screw;

Fig. 11 is a fragmentary detailed section taken substantially 'on the plane of line i I-I I of Fig. 5;

Fig. 12 is a fragmentary section through the stuffing box assembly, showing a modied form thereof;

Fig. 13 is a view similar to Fig. 12 showing a further modioation of the stuffing box assembly; and

Fig. 14 is a view similar to Fig. 12 showing a still further modication of the stufng box assembly.

The main features of the invention include a sectional housing A made of metal or acid resisting metal; a sectional centrifugal pump casing B which may be made of corrosion resisting ceramic, or vitreous material such as glass; a driven member I, which in the form illustrated is an impeller made o the same material as the pump casing; a metal drive shaft C to which, by a unique coupling, set forth in the United States patent application, Serial No. 310,462, filed December 21, 1939, in the name of Harold E. Adams and Willard A. Kates, now Patent No. 2,283,348, is anchored to the driven member I; a prime mover in the form of an electric motor M; and a stuffing box assembly H, which, as will presently appear, includes a peculiar construction of gland and special seal elements in position under a uniform and controlled pressure. The sectional metal housing A provides a l port for clamping the sections of the glass pump casing B together under a uniform predetermined spring pressure to prevent crushing of the frang- ""ible casing sections. The metal housing also furfollower sleeve elements that retain suplocked in position while subsequent leg 24 is an interrupted nishes a protective guard about the casing to prevent breakage, and prevent injury from flying glass in event the casing is broken. All of the outside metal parts of the present invention, including the metal housing, may be made of cast iron, or other metal, not necessarily highly resistant to acid, and acid vapors, and such metal parts may be cadmium plated or covered with rubber base paints and other acid resisting coatings.

The housing A is formed in two parts, or sections, the inner of which consists of a bracket cage composed of four spaced legs 20 which straddle the drive shaft C. At one end the legs 20 join with a ring 2l which may be bolted as at 22 to the motor M surrounding the shaft C. At the other end the legs 20 join with a circular ring `member 23a which is angular in cross section.

This ring member 23a. isformed with a radially extending leg 24 and an axially extending leg 25.

The outer section of the housing A is formed of a bell-shaped cover 26a and is composed of a flange 21 around its periphery that merges with a crown in the center of which is a round opening, the walls 28 of which are inclined for a speciiic purpose of coacting with the adapter pipe as will presently appear.

The sectional glass pump casing B, which inl the form illustrated, is for a centrifugal pump, has a round head section 29, detachably seated on the \radially disposed leg or side 24 of the ring member 23a with a resilient gasket 30 in between to protect the glass.

The edge of the bowl-shaped volute section 3| of the pump casing has the inner edge bearing on the periphery of the head 29 with a resilient gasket 32 in between, thereby providing a centrifugal pump chamber 33 between the head and volute sections, in which chamber the impeller I rotates. The periphery of the volute part 3| bears against a ledge on the inside of the cover 26a with a resilient gasket 34 in between. At the center, the crown of the volute section 3l merges with an integral round suction nozzle 35 having a smooth surface on the outside. The nozzle 35 extends outwardly from the volute section 3| and provides the inlet port for the pump chamber 33.

On the inside face of the' radially extending ring 31 formed with outstanding tongues or lips 38 on the solid parts or segments of the ring. The interruptions or spaces between the segments are indicated at 39. Around the outer edge of the head 29 is a flange lill which is likewise interrupted by spaces 4l to correspond with the length of the segments of the interrupted ring 21, and having solid parts or segments corresponding to the length of the interruptions or spaces 39 in the ring, allowing practical clearances for insertion and removal of the head 29. When the head 29 is positioned with the solid parts or segments of the flange 40 registering with the spaces 31 between the lips 38, and with the spaces 4| between the solid parts of the flange 40 registering with the lips 38, is pressed inwardly and turned on its axis, the flanges 40 are temporarily locked on the solid parts of the ring 31 behind the lips 38. It will thus be seen that the head part of the pump casing assembled, is temporarily parts are 29, which is the first' mounted. In the completely assembled relation there will be a clearance (as shown in Fig. 9) between the ring 31, the lip 38 and the ange 40, when the parts are centered because vibration might occur in the operation of the pump and tend to break the head 29 if these parts were in normal contact.

To assemble the volute part 3|, it is placed in position against the gasket' 32 on head 29 and rests on two adjusting screws 42, which screws are spaced apart about a quadrant and these screws are mounted in threaded openings in lugs 43 (Fig. 9) formed on the radial side 25. These screws 42 serve to center the volute part 3|, and in the centered position, the screws maybe locked by screwing the nuts 44 against the lugs 43. After positioning the volute part 3| it is locked there during the balance of the assembly operations by means of a locking screw 45 (see Fig. 10) and this screw has a threaded shank engaged in a threaded opening on a lug 46, which lug extends outwardly from the side 25. The screw 45 has a rubber tip 41 imbedded in the shank and the tip bears against the rim of the volute part 3|. (See Fig. 10.) In centered position, the screw 45 is locked by the nut 48 mounted thereon which bears against the face of the lug 46. It will be seen that by this arrangement the head 29, and the volute part 3| are held from dropping out of the ring member 23a while the operator makes ready to attach the cover plate 26a of the hous- In order to secure the cover plate 26a in position, a plurality of equidistantly, circumferentially spaced studs 5| (see Fig. 8) have reduced threaded inner ends 52 anchored in threaded openings in the outset flange 53 on the outside of the leg 25 of ring 23a. The number of studs 5| used varies with the requirements of the installation, and for the purpose of illustration eight' studs are shown. An intermediate portion of the studs is smooth and extends with clearance through openings 54 in the periphery of cover plate 26a, which openings correspond in number and position with the threaded openings on flange 53. A portion 55 at the outer end of the studs 5| is threaded. Between the threaded part 55 and the smooth part is the limiting shoulder 56. After the cover plate 26a is positioned on the studs 5|, a spring 58, the function ofwhich will appear later, is placed over eachof the studs,`

bearing on the cover plate 26a. Then a nut 59, having an integral threaded sleeve 60, is placed on the threaded portion 55, with the sleeve 60 inside the spring and no matter how the operator tries he cannot screw the nut and sleeve back farther than the shoulder 56 in consequence of which the springs 58 will all be placed under a uniform predetermined compression which insures against crushing and breakage. If it were left to the operator to select the pressure, it might provoke an error and result in applying too much pressure on the frangible parts 29 and 3| whereby they would be crushed and broken. It is also obvious that by selecting springs 58 with the proper tension to meet the requirements of the factors attendant with the glass casing, a predetermined pressure is exerted between ring 23a. and cover plate 26a of housing A, which is translated to the sections 29 and 3| of the pump casing B. Should pressure in the pump casing exceed the predetermined amount, the housing sections will separate, and the casing sections will part along the' gasket 32 whereby the increment of pressure is released. When the increment of pressure escapes, the housing and casing return to closed position imder the normal compression of springs 58.

It is pointed out that the outer periphery of the volute part 3| which is initially resting on the centering screws 42 and 45 inclines (see Fig. 9) inwardly as at 51, and when in the assembled relation the pressure of springs 58 is exerted, the compression of the gaskets 30 and 32 permits movement inwardly. This action causes the periphery of the volute to recede from the 4centering screws and provide a slight clearance between the tips of the screws and the periphery of the volute part 3|.

Any acid or other liquid that escapes when the parts 29 and 3| of the pump casing part along the gasket 32, runs down the inside of the ring 23a to the lowest point where an opening 63 permits it to escape. It may happen that the pump casing sections 29 and 3| stick together, and to meet this contingency a second opening 64, spaced about a quadrant from opening 63, is made in the side 25 of housing section 23a, positioned to lie along thehorizontal diameter when the opening 63 is at the bottom so as to obtain proper leverage. On the rim of the volute section 3| of the casing, in the vicinity of openings 63 and 64, raised cleats 65 and 66 respectively are molded so that a pry bar may be fulcrumed on either enough to interfere with Ithe flange 40 on head 29 of the pump casing.

Since the respective lugs 43 and 46 which support the centering screws 42, and the clamping or locking screw 45, lie in the extended plane of the axial side 25 of the ring 23a, it will be necessary to modify the flange 21 at these points. To accommodate the lugs and the screws, the flange is cut away at 6B which corresponds in position to the screws, and surrounding the openings are skirts or arches 69 (see Fig. 9).

The glass impeller I that rotates in the pump chamber 33 is formed as a' disc 1| having impeller blades 12 formed on its forward or suction face. tion. On the opposite face of the disc, and staggered with respect to blades 12 are formed the blades 13. The blades 12 and 13 are cast or molded integrally with the disc 1|. It will be seen that, the blades 13 are of materially less height than blades 12, and the former blades serve to lessen the pressure in the stuifing box and sealing area to reduce the leakage of liquid. The blades on both sides of the disc are designed to have a close clearance with the side walls of the pump casing confronting them. From the center of the disc 1| there projects rearwardly an integral hub 15 that extends entirely4 through the stuing box or seal chamber 16 formed by the stufng box neck or extension 11, in spaced These blades perform the pumping funcassenso the sealing elements, as`wil1 presently appear. Owing to certain factors in various installations, it may be necessary under certain conditions to provide a direct connection communicating with the pressure side of the pump, and to meet this condition an opening 80 may be made in the disc (see Fig. 14) adjacent the hub, which opening is disposed in axial alignment with the stumng box or seal chamber 16.

On the outside of the extension 11 near the end thereof is an inset seat 8| for receiving a rubber band 82 which latter grips the neck snugly. It is the purpose of the band to direct any stray acid that may escape from the stuing box assembly into the funnel member to be presently described. This band .82 is furnished in lieu of molding a corresponding rim on the glass extension owing to the difficulties of molding practice. When acid encounters the band 82 it will be impeded in its progress, and it will run down the band to the lowest point and drip off as indicated.

In the area where the discharge nozzle 83 projects, the walls 0f the rim 23a and cover plate 26a are cut away suiiiciently to allow for the projection of the nozzle without contact with the metal.

The Walls of the nozzle 83 are preferably molded or cast integrally with the volute part 3|, so that it will move with this section when the cover plate 25a and the volute part 3| separate under excessive pump pressures.

Referring now to the form of the stuffing box assembly H, illustrated in Figures 1 and 11, there is shown one way of devising a unique shaft seal in a, manner to dissipate and transfer frictional heat to the liquid being pumped, so as to avoid transmission of the heat to the glass impeller I, the glass covered drive shaft C, and the glass stufling box extension 11. It will be seen that the extension 11 is formed integrally with the head 29 and would be likely to be broken from excessive heat. Should no provisions be taken to dispose of the friotional heat developed, by

having glass wiping glass, it will be evident that the heat would break the glass casing B and impeller I.

Various attempts to make a satisfactory glass centrifugal pump have resulted in failure largely because of the diilculties encountered in the provision for a suitable stuffing box to prevent the outward leakage of corrosive uids being pumped along the shaft. This diiiiculty revolved mostly about the inherent low coefficient of heat transfer of glass, together with the fragile nature of vthe glass itself. Any rubbing friction as would be occasioned by the conventional stuffing box construction would result in a localized heating of the hub 15 and this in turn would cause the cracking of the glass. In this invention there is provided a practically leak-proof seal which at the same time overcomes these diiculties. Owing to the low coefficient of heat transfer, or low conductivity of heat in glass, it will have different stresses and strains set up in a spot heated locally, from the unheated surrounding region. The lack of uniformity in the stresses and strains at the heated spot will be sufficient to rupture the glass and this characteristic is known as heat shock.

In devising the proper elements for the stuiiing box, it is necessary to provide as one of the sealing elements an acid resistant seal in the chamber 16 to prevent acid seepage along the hub 15 of the impeller. Toward this end there is provided a rotating glass collar 84, which in the form of the invention .shown in Figures 1 and 11,

forms one of the sealing elements. The rotating seal element B4 may be made of such acid resist-n ing materials as high chromium and nickel steels, or compositions including phenolithic compounds and Micarta. The collar or seal element 84 is pressed on the glass hub so as to rotate therewith, and there is a exible gasket interposed between the collar 84`v and the hub 15. This gasket is right angled in cross-section and supports the sealing element or collar 84 in spaced relationV with respect to the inner face of the impeller and the hub 15 thereof. The gasket 85 is formed of rubber-like materials that are inert to most acids and other corrosive fluids, andat the same time this gasket furnishes the maximum heat insulation to prevent the exchange of heat between the glass collar 84 and the impeller I and the hub 15. On the outer periphery of the collar is a lip 8S which overhangs the radial leg of the gasket 85 and holds the gasket against distortion or swelling caused by centrifugal force. The free face 81 of the collar is flat and is provided with a highly polished surface which in the stuffing box assembly, illustrated in Figures 1 and 11 of the drawings, forms the movable or rotary part of a seal. This seal prevents the pump chamber 33 from communicating with the exterior of the casing when the cooperating parts of the seal function.

The flexible insulating element 85 serves to insulate the glass seal element 84 from the impeller I, so that any heat developed on the rotating sealing surface 81 will not be transmitted directly to the glass impeller itself. This iiexible insulating element 85 also provides for the automatic positioning of the sealing surface 81 in a plane at right angles to the axis of rotation of the impeller, thus eliminating any leakage diiculties that might be caused by any run-out of this surface.

The stuiiing box assembly H further includes another seal element in the form of a ring 9| positioned in the chamber 16 in spaced relation to the Wall 18 and in spaced relation to the hub 15. Thisring 9| does not rotate, but it is urged axially into a. central position and bearing relation by the action of the gland and the follower parts of the stuffing box assembly H to be presently described, with the rotating sealing face 81 of the rotating sealy element 84. It will be seen that this arrangement provides a predetermined required pressure for proper contact between ring element 9| and collar element 84 at the sealing surface 81, In actual practice, the ring 9| is made of carbon, graphited carbon, or graphite, although any other materials suitable for the acid service contemplated, that have a high coefcient of heat transfer, would be suitable.

It will be seen in the form of the invention shown in Fig. 11 that'the element 84 and the ring 9| are spaced from the chamber wall 18 so that the liquid being pumped is free to circulate through the conduit 19 or 80 (in the form of the invention shown in Fig. 14) and contact the high heat transmitting element 9| and thereby dissipate the heat to the liquid being pumped. It is pointed out that the function of the ring 9| is to readily absorb the heat developed by the friction at the sealing surface 81 and dissipate it to the liquid being pumped and away from the glass parts that are likely to be injuredby localized heating, or by heat shock.

Next to the high heat transmitting ring 9| is aesassa a resilient compensating ring 92, the inner periphery of which is supported in spaced relation to the glass hub 15. This compensating ring has the outer periphery thereof bearing against the wall 18 of the stuiilng box or seal chamber 16, and the inner face bears against the high heat transmitting element 9|, Ring 92 is so proportioned in the stuiiing box assembly that it is completely confined except for a. small annular section ontwo sides of the ring indicated at 93 and 91|. This annular section is left unsupported on the sides so as to give some degree of freedom to the endwise movement of the ring 92, to compensate for any Wear that might occur at the lsealing surface 81, and which movement results from the spring pressed gland and follower elements, as will presently appear, wherein the springs are so proportioned as to give the required pressure for proper contact between the sealing surfaces 91. The compensating ring 92 is preferably made of a rubber-like resilient material. The sealing action caused by the expansion of the compensating ring 92 outwardly against the wall 18 is somewhat analogous to the corking obtained when a cork in a bottle swells under the influence of liquid contents.

The compensating ring 92 being resilient, ac-

complishes two functions when compressed by the gland and follower member to be described later, the said ring expands outwardly effecting a tight' seal between the impeller hub 15 and the wall 18, by its engagement with the reduced portion 95 of the follower ringy and at the same time it Permits a iiexing caused by the pressure of the gland and follower ring, to be presently described, such that wear of the compensating ring is automatically taken up regardless of how tight a seal is being maintained against the wall 18.

It will be noted that it is not necessary to provide for the absolute concentric relationship of the seal elements 84 and 9|. The centering that is provided by the stumng box assembly shown, is entirely sufficient as there is no requirement for peripheral clearances or fits. The only requirernent is that the seal surfaces at 81 operate in a plane perpendicular to the axis of rotation of the impeller I. This perpendicular plane is obtained by the self-aligning features of the various component parts of the stuiilng box assembly, principally the rotating flexible member or gasket 85 and the stationary exible compensating ring 92.

In the form of the invention shown in Figures 1 and 11, the follower ring has a reduced part 95 surrounding the hub 15 in spaced relation and on this reduced part rests the compensating ring 92 and a portion of the high heat transmitting ring 9|. The enlarged portion 96 of the follower ring projects out of the chamber 16 for engagement with the one side of the deector gasket 91. This follower ring is preferably formed of glass and in the outer face of the enlarged part is a cavity 99. The shoulder formed between the reduced part 95 and the enlarged part 96 of the follower ring bears in the outer face of the compensating ring 92 and transmits pressure to the inner elements of the stuiiing box. The inner periphery of the reduced part 95 of the follower ring is spaced at 99, from the hub 15 of the impeller and this space allows any seepage along the shaft to creep into cavity 98.

In addition to the follower ring, the stuffing box assembly H also includes the gland I9 la and this gland is preferably made of acid resisting metal. In the center, the gland |9|a is formed with a cup-shaped part |92, the rim of which bears against the outer face of the deector gasket 91. The cavity |93 in the cupped part |92 corresponds to the cavity 98 inthe follower ring.

It will be seen that the deflector gasket 91 divides the cavity 98 from cavity |92, there be-l ing a central opening in the deiiector gasket surrounding the hub 15, A rubber slinger band |95 is secured to the hub 15 in the cavity 98 and an other slinger band |96 grippinglyv engages the hub 15 in the cavity |93. 'Ihe slinger bands |95 and |99 being rotatable with the shaft 15, throw seepage along the hub out into the respective cavities 98 and |93 from where the seepage is drained. For the purpose of draining cavity 98 in the follower ring, a groove |91 is made in the outer edge, while a like groove |98, on the other side of the deflector gasket 91, made in the rim of the cup part |92 of the gland, drains the cavity |93. The grooves |91 and |98 are formed in the lowest segment of the follower ring and cupped part |92 respectively, and are located over the mouth of a lead funnel member H9. This funnel member has a pair of arms III iixed to the opposite sides and the arms rest upon opposed legs 29 of the lower pair of legs, the` funnel extending between the legs. seepage drips into the funnel member and is directed to any character of receptacle desired. 'I'he outlet grooves |91, |98 register with each other and through the opening formed thereby extends a tongue H2. The tongue |I2 is formed as an extension on the bottom segment of the deiiector gasket 91, which gasket is clamped in position between the confronting ends of the cupped part |92 and the follower ring. Any seepage along the hub 15 will be deflected by the gasket 91, run down the gasket to the tongue of the deiiector 91 and drip into the funnel l I9'. It will thus be seen that there is created in the gland and follower members a collecting chamber composed of the confronting cavities 98 and |93 respectively, which collecting chamber is bridged by the novel arrangement of the deflector gasket 91 that when cooperating with the slinger bands |95, |96 and the outlet grooves |91, |98, affords a triple precaution against leakage of corrosive liquids from the stuffing box assembly. A pair of round guide posts ||2 have their` inner ends anchored in threaded openings I3 on the ring 2| of the inner housing section. The posts I2 extend outwardly of the ring 2| and axially of the drive shaft C'. The posts are positioned to extend through rounded portion lil at the inner end of slots I|5, one slot being in the outer portion of each wing IIS, |I1 of the gland |9|a. One slot ||5 enters each rounded part I9, one from one side of the one wing, while the other slot enters from the opposite side of the other wing, and when spring tension, as will presently appear, is removed, the gland |9|a may be separated and moved outwardly from the balance of the stuffing box assembly by simply turning the gland so that the wings slip away from the posts H2, since the slots |'I5 provide a space through which the posts may pass.

A controlled and predetermined pressure is exerted on the gland |9|a and transmitted to the balance of the stumng box assembly, by the tension afforded by the springs ||8, one of which encircles an intermediate part of each post l2. Factors which determine this pressure may vary with each installation, butvit should be sufficient to overcome the normal pump pressures reacting accanto on the elements 84. 9|, 82, 91, and the follower ring. At their outer ends the springs bear against a flange li 9 on a bushing |20 which extends through the rounded part I4 and slots H8 in the respective wings H8, H1. The iiange I |9 seats in a groove |22 about the rounded part H4 whereby the bushing is locked under tension. The bushings |20 slide on a, threaded part |23 of the posts ||2 and on the outer end of the threaded pari'l of the posts, the nuts |24 are mounted. The outer end of each bushing projects above the face of the wing, as clearly shown in Fig. 11, so that when nut |24 is screwed tight against the projecting end the iiange ||9 will be forced out of the groove |22 so that pressure is removed from the gland when it is desired to dlsassemble the stumng box assembly H.

One end of the control springs ||8 bears against the flange ||9 on the bushing, while the other end bears against the outer face of 4ring 2|, all of which provides a, resilient controlled pressure on the gland which is in turn transmitted to the successive elements of the stuing i box assembly.

The amount of pressure necessary with each application may be controlled through the springs ||8 and for this reason the springs are selected to supply a predetermined pressure. The amount oi' pressure to be supplied, and consequently the strength of the springs, will depend upon the necessary pressure required at the sealing face 81, and also the normal pump pressure in the pump chamber 33. Thus therewill be a. uniform and controlled pressure at the sealing surface 81, that is insured because the controlled pressure cannotv be altered. In the event pressures are developed in the Vpump chamber 33 in excess of the pressure for which the pump was designed, the springs H8 will permit any or all of the elements 84, 9|, 93 and thefollower ring and the gland elements to move outwardly and permit the increment of pressure to escape.

In the stuiling box assembly H there is provided the elements making up the seal including the intermediate elements 84 and 9| which are separated from the glass of the hub 15 and the extension 11 by the heat insulating layers in the form of the rubber-like gasket 85 and the exible rubber-like compensating ring 92. The intermediate members 84 and 9|, aside from forming a seal at the contacting surface 81, are selected to provide characteristics to'prevent the exchange of heat with the glass pump casing and the drive shaft which has the glass hub 15 surrounding it. I! both members 84 and 9| were made of a material having a low coefticlent of heat transfer, like glass, the heat developed by the friction at the sealing surface 81 will not be dissipated to the liquid being pumped rapidly enough to prevent a burning or scorching of one or both surfaces. If one or the other of the members 84 and 9| does not have a high coeiiicient of heat transfer and at the same time is operating in conjunction with a glass rotating member 84, the heat developed will be sufficient to crack this glass member 84. As long as one or the other of these two members 84 or 9| is a high conductor of heat, it will prevent the cony centration and building up of heat at the sealing face 81 because the heat will be freely-transmitted to the liquid being pumped. In the stuifing box assembly shown in Figures 1 and l1, the graphite seal ring 9| is the element that has the property of conducting heat from the sealing surface 81 and transmitting the same freely to the ditions such as handling high solvents, and other hot liquids, where the temperature is higher than safely can be withstood by the molded flexible rubber-like materials used in the gasket 85 and the compensating ring 92 of the stuiiing box assembly shown in Figures 1 and 11. To accommodate the higher temperature, in a range that would soften, and make tacky, these rubber-like materials, it is necessary to modify the stuing box assembly H shown in Figures 1 and 11, and as disclosed in Figures 12, 13 and 14.

In the forms of the invention illustrated in Figures l2, 13 and 14, the impeller 200 isconstructed the same as the impeller I shown in Figures 1 and 11 of the drawings, having blades 212 and 213 formed integrally with a disc 21|, which blades and discs are formed likethe disc 1| and blades 12 and 13, except there is shown an opening in the disc which provides an additional conduit from the high pressure side of the pump to the seal chamber to insure a circulating liquid. In the forms of the invention shown in Figures 12, 13 and 14 there is a 'conduit 219 between the blades 213 to furnish the stuffing box chamber or seal chamber 216 with the liquid being pumped for the purpose of dissipating frictional heat. The conduit 219 and stuffing box chamber 216 are alike in all respects with the conduit 19 and the seal or stuiiing box chamber 16 as shown in the form of the invention illustrated in Figures l and 11.

It is also pointed out that the construction shown in Figures 12, 13 and 14 provide a radial shoulder |30 on the impeller 200 which is similar to a shoulder on the impeller I and in these forms of the invention the hub 215 is formed similarly to the hub 15, the hub being coupled to the drive shaft 300 through a metal quill and solder or cementitious bond, as will be hereinafter described. In the form of the invention shown in Figures 12, 13 and 14 the head 290 of the pump casing is formed like the head 29 illustrated in Figures 1 and 11, having the stuing box neck or extension 211, the stuiilng box chamber 216 dened by the wall 218 similar to the extension 11 and chamber 16 in the form of the invention shown in Figures 1 and 11; and likewise the gland 2|l|a is similarly placed under the tension of springs similar to the springs ||8 in the form of the invention shown in Figures l and 11 of the drawings.

In Figure 12 there is a rotating ring 30| made of graphite, graphited carbon or carbon, which surrounds the hub 215, and one side of this ring abuts the shoulder |30 on the impeller 200. The

the outerV periphery. It will be seenthat any heat developed on the sealing faces will be transmitted by this ring to the liquid. The other side of the seal ring element 30| is provided with a convex highly polished spherical surface 302 and rotates in rubbing contact with a correspondingly concaved face on the glass member 303. The member 303 is in the nature of a piston which is free to move in the stuffing box chamber 216. The inner periphery of the piston member 303 surrounds the drive shaft C in spaced relation, while another portion flares outwardly to provide a cavity 304 similar in structure and function to the cavity 98 in the follower ring disclosed in Figures 1 and 11 of the drawings. This cavity 304 forms the inner part of the collecting chamber that is constructed like the collecting chamber shown in Figures 1 and 11.

The outer periphery of the glass follower ring or piston 303 is formed with labyrinth grooves 305 confronting the chamber wall 216 so as to be free to move in the chamber, but at the same time to prevent excessive leakage at the joint between the chamber wall and the outer periphery of the ring. There is not a great pressure difference at this joint mentioned above because of the provision for maintaining substantially atmospheric pressure in the chamber 216 created by the counteraction of the blades 21|, explained in connection with blades 1| in Figures 1 and l1 of the drawings. Because of the spherical seat 302 the ring 30| will automatically adjust itself so as to completely engage and seal the impeller hub 215. Leakage of liquid from the interior of the pump along the joint between the labyrinth grooves 305 can, therefore, be minimized or stopped by the sealing surface 302. All of the materials used in this particular stuffing box assembly shown in Fig. 12, are resistant to much higher temperatures than in the assemblies shown in Figures 1 and l1, due to the elimination of the rubber-like elements 85 and 92, and although a slight leakage may occur, this leakage will be held to a minimum with a satisfactory seal resulting.

The stuffing box assembly shown in Fig. 13 has a ring 3|| formed of graphite, graphited carbon, or carbon, that encircles the drive shaft in spaced relation thereto. This ring 3|| has a radial face 3|2 and another radial face 3|3 which maintains a seal between the interior and the exterior of the casing. The surface 3|2, and

' 3 I 3 can both be polished, together with their mating surfaces |30 on the impeller 200,. andthe confronting end of the glass piston-like element 3M, sc as to provide a differential rotation of the ring 3|I, said ring assuming a rotational speed of approximately half of the impeller 200. No provision is made for a self-alignment of the ring or element 3|| in the assembly shown in Fig. 13, like the spherical surfaces302 in the form of the invention shown in Fig. 12.

The glass piston-like element 3M, shown in Fig. 13, has a reduced end on which an acid resistant, high temperature gasket 3|5 is seated to reduce possible leakage at the joint 3I6 where the outer periphery has a clearance with the wall of the stulng box chamber 216. There are labyrinth grooves 3|1 similar to the grooves 305 on the glass element 303 in Fig. 12 of the drawings. A glass follower. ring 3|8 holds the gasket 3|5 in place and also forms a closure or cover for the inner portion 2|9 of the collecting chamber. This cavity or chamber 2|9`funotions similarly to cavity 98 in the form of the invention shown in Figures 1 and 11 of the invention. The material from which the gasket 3|5 is made is preferably asbestos, and the gasket can be cut tightly to the shoulder |30 on the impeller 200.

Like the gasket 3|5 in Fig. 13, the gasket 322 is designed to be cut from flat pieces, or sheet material from stock, which is easily obtained in acidresistant, high temperature resisting materials, such as asbestos or woven glass. The rotating seal ring 32| provides a construction which allows it to be replaced when it becomes worn, and is desired above the assemblies shown in Figures 12 and 13, inasmuch as the wear occurs on these latter constructions against the shoulder i 30 of the impeller. In the construction shown in Fig. 14, the carbon ring 323, bears on the outer polished face of the rotating glass seal ring 32|,to provide the radial seal 324. While the insulating ring gasket 322 provides a certain degree of insulation against the transfer of heat to the impeller 200, the glass ring 32| is not as fully insulated as the glass ring element 84 in Figures 1 and 11, in that there is more contact between the impeller hub 215 and the inner peripheries of the glass ring 32| and the carbon or graphite ring 323 respectively at 325 and 326.

In Fig. 14, the piston-like sleeve element 321, the gasket ring 328 and glass follower ring 329 are constructed like the corresponding parts 3M', 3|5, and 3|8 respectively, in Fig. 13, and their functions arethe same as said corresponding parts.

In the forms of the invention shown in Figures 12, 13 and 14, a means is provided to prevent the member abutting the inside of the deflector gasket 391 from turning, and this gasket is s milar to the gasket 91 in Figures 1 and 1l, exc t as hereinafter indicated. Toward this e'nd a pin has an intermediate portion secured transversely in the gasket 391 with opposite ends 398 and 399/,y projecting outwardly of this deflector gasket. The' one end 398 engages in a slot 400 in the, glass element 303 in the assembly shown in Fig. 12. In the structure shown in Figures 13 and 14, the end 398 ofthe pin is engaged in the slot 40| in the follower rings 3|8 and 329, respectively, The other end 399 of the pin engages in a slot 402 in the hub of the gland 20|a. By the engagement of the end 398 of the pin in the slots 4,00 and 40| respectively, the respective elements- 303 and 3|8,

329 are denitely positioned and at the same time f and 14 of the drawings, the construction is simii lar in all respects to the structure shown in Figures 1 and 11 of the drawings.

It has not been considered practical or ex/ pedient to use, in the suction line 50| (see Fig. 1), the customary glass pipe line fitting, as indicated at F in the discharge line 502, and as a result it is necessary to devise a special fitting. It will be observed that the end of the suctionnozzle 35 terminates at, or short of, the crown of cover plate 26a in a male end 503 in alignment with the opening dened by wall 28. An adapter pipe member 501i provided with a female end 505 receives the male end 503, and this member 504' extends through the opening in the crown of the 15 cover plate 25a. The outer end of the adapter member 504 is joined by the conventional glass pipe fitting, similar to that indicated at F, to the suction line 50|.

It will be understood that all of the metal to glass joints, as F, and at the suction line 50|, will be equipped with suitable packing. in a conventional manner.

Surrounding the female end 505 is a ange having the surface provided with an inward inoline 506, which coincidesl with the corresponding incline of the Wall 28 of the opening in cover plate 26a. This wall 28 has a split-rubber lining, insert or washer 501 secured thereto, so that when the fitting is drawn tight the metal wall 28 will not crush the adapter. Adjacent the male end 503, there is a rubber ring 508 pressed on the nozzle. The ring is of right triangular cross section, so the base will abut the edge of the ange of the adapter, and the hypotenuse side 509 inclines upwardly and outwardly from the apex. The incline at 509 is about the same pitch as the incline at 506. With respect to the ineline 505 on the flange, the side 509 on ring 508 forms an anti-clinal surface all around the joint, an intermediate part of which surface is interrupted or divided by the joint between the nozzle and the adapter. y

A collar is disposed on the ring 508. The Wall 5|2 about the opening in the collar is inclined in a plane that substantially coincides with the incline 500 on ring 508. The wall 5|2 and the wall 28 of the opening in the cover plate 26a, form an interrupted synclinalsurface with respect to the collar 5| I and cover plate 26a considered conjointly, all round the respective openings. The openings which these synclinal surfaces surround are neither of them as large in diameter as the apex of the anticlinal surface on the flange and ring. Such being the case, when one of the synclinal faces move toward the other a wedging action is applied to the anticlinal surfaces 50S-506, and the reverse movement releases the wedging action.

On the outer periphery of the collar 5| I, there are ears 5|3, preferably three in number. Anchored in threaded openings, one in each ear, is an outwardly projecting stud 5M, an intermediate portion of which extends through openings 5|5 in the cover plate 25a. On the projecting end of each stud 5|4 there is a Wing nut 5|6, which, when the parts are assembled as shown in Figure l, supplies the force to wedge the parts togetherand make a tight fitting between the adapter and the nozzle. A tight seal is provided between the edge of the flange on the female end of the adapter and the altitude side of the rubber ring 508, and a groove 5|1 is molded around the edge of the adapter to provide an additional sealing means.

When these component parts of the fitting are assembled in the position shown, the collar 5|| is pulled into position by means of the wing nuts SIG. In tightening up all these wing nuts, it; will be observed from the drawing that this provides for the compression of the resilient ring 508 s o as to tightly grip the cylindrical surface of the nozzle 35 and at the same time to come up hard against and tightly seal oif the end of the suction adapter pipe 504.

Invention is not claimed for these various elements per se, as many of them are used in connection with glass piping practice but what Ibelieve is novel is the use of these devices as indicated sc as to provide more or less rigid means of connection of the suction pipe to the glass suction nozzle of the pump, in a manner so as to remove the pipe strains from the glass pump member itself. In this connection it will be noted from the drawing that the adapter pipe 504 is held rigidly in position through the medium of the metal cover plate |1a. This provision removes any strain of the suction piping from the glass parts of the pump itself. Such strains would, of course, be liable to break the expensive volute portion 3| which at this point would otherwise be relatively unsupported and, furthermore, strains at this point would be liable to interfere with the working clearance of the impeller.

Considerable difficulty has been experienced in making a rotary joint betweenV a metal drive shaft C, and a rotary driven member such as the impeller I. The rotary joint hereafter described Vis the subject of the above mentioned application and for the purposes of the present invention, it is sufficient for an understanding that the rotary joint between the shaft C and impeller I is made by forming a socket 520 in the hub 'l5 of the impeller I. The wall of the socket is formed with irregular cavities 52|. A hollow spindle or quill having an enlarged head 522 is formed with a reduced inner part 523 (see Fig. 11) which terminates in a tang 524 that registers with a cavity 525 in the end wall of the socket 520. The surface of the reduced inner part 523 is irregular as at 526. (See Figs. 6 and 7). There is a space between the irregular cavities 52| in the socket wall and the irregular surface 52B on reduced part, and this space continues between tang 524 and cavity 525, and in this space is a hard solder or cementitious bond '521 which has the property of expanding while congealing from the liquid or plastic phase to the solid phase. The bond 521 forms a mechanical lock with the irregular surfaces that prevents longitudinal and rotary movement between the impeller and the quill.

The stub drive shaft C fits in a socket 528 in the quill. The quill is keyed to the drive shaft C by a key 529 (see Figures 6 and 7), one half of which seats in keyway 530 in the wall of the socket 528, and the other half seats in a keyway 53| in the drive shaft C. A positioning set screw 532 (see Figure 5) is threaded in an opening in the enlarged part 522 of the quill, and the inner end of the set screw seats in an opening 533 in the shaft. A second set screw 534 is mounted in a threaded opening in the enlarged part 522 of the quill at about ninety degrees from the set screw 532 and the inner end of this set screw bears against the periphery of the drive shaft C.

This second set screw 534 applying force to the shaft C at right angles to set screw 532, reduces to a minimum any play between the shaft and metal quill.

This application is a division of my co-pending application, filed May 25, 1939, Serial No. 275,755, now matured into Patent No. 2,347,386 of April 25, 1940.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of theUnited States is:

1. In a vitreous pumping unit having a vitreous pump casing and a vitreous pumping means therein both of which are sensitive to heat shock, seal elements disposed between the casing and pumping means, means for maintaining said seal elements in rubbing sealing contact during normal running operation of the pumping v of said pump casing and said pumpingmeans,

to prevent heat shock in the casing and pumping means, one heat insulating element being in Contact with the casing and one sealelement during normal running operation-of the pumping unit, and another heat insulating element being` in contact with another seal element and the pumping means during normal running operation of the pumping unit.

2. In a vitreous pumping unit having av vitreous pump casing and a vitreous pumping means therein both of which are sensitive to heat shock, seal elements disposed between the casing and pumping means, means for maintaining said seal elements in rubbing sealing contact during normal running operation ofthe pumping unit whereby frictional heat. is developed, heat insulating elements of material substantially more resistant to heat shock than the material of said pump casing and said pumping means, to prevent heat shock in the casing and pumping means, one heat insulating element being in contact with the casing and one seal element during normal running operation of the pumping unit, and another heat insulating element being in contact with another seal element and the pumping means during normal running operation of the pumping unit, and one of said seal elements being formed of material having a higher coeicient of heat transfer than the parts sensitive to heat shock.

3. A rotary liquid pump comprising a glass pump casing providing a pump chamber, said ceasing being further provided with a stuffing box chamber, a rotary glass impeller in the pump 'seal elements having a higher coefficient of heat transfer than glass, and means establishing a conduit between .said seal elements and the pump chamber whereby heat may be transmitted to the liquid being pumped..

4. In a pump having a pump casing and impeller therein and driving means for said impeller, a stuiiing box assembly between the driving means and the casing, one member of said assembly cooperating with said'driving means to form a seepage collection chamber surrounding the driving means, and otherelements of said assembly cooperating with the driving means to form a second seepage collection chamber, means in said seepage chambers to centrifugally deect seepage from the driving means into said chambers, one of said second mentioned elements forming a partition separating the seepage chambers from each other, and said partition providing a path for capillary flow of the deflected seepage' away from said chambers, and drain means adjacent said last mentioned element for escape of seepage from the chambers.

5. In a pump having a pump casing and im peller therein and driving means for said impeller, a stuiling box assembly between the driving means and the casing, one member of said assembly cooperating with said driving means to form a seepage collection chamber surrounding the driving means, and other elements of said assembly cooperating with the driving means to form a second seepage collection chamber, means in said seepage chambers to centrifugally deect seepage from the driving means into said chambers, one of said second mentioned elements forming a partition separating the seepage chambers from each other, and vsaid partition providing a path for capillary flow of the deflected seepage away from said chambers, drain means adjacent said last mentioned element for escape of seepage from the chambers, and means on said partition forming elementl to hold an adjacent element of the assembly from rotary movement.

6. In a pump having a pump casing and impeller therein and driving means for said impeller, a stufing box assembly between the driving means and the casing, one member of said assembly cooperating with said driving means to form a seepage collection chamber surrounding the driving means, and other elements of said assembly cooperating with the driving means to form a `second seepage collection chamber, means in said seepage chambers to centrifugally deflect seepage from the driving means into said chambers,

one of said second mentioned elements forming pump casing providing a pump chamber, said ibox chamber, in spaced relation to the wall thereof, seal elements between the hub and the stufling box chamber wall, at least one of said seal elements having a higher coeiiicient of heat transfer than glass, means establishing communication between said seal elements and the pump chamber whereby heat may be transmitted to the liquid being pumped, and means to maintain a reduced pressure in said communication means.

8. A rotary liquid pump comprising a glass pump casing providing a pump chamber, said casing having a stuffing box chamber, a glass impeller operable in the pump chamber and provided with a glass hub extending into the stufng box chamber, in spaced relation to the wall thereof, seal elements between the hub and the stufiing box chamber Wall, at least one of said seal elements having a higher coefficient of heat transfer than glass, means establishing commu nication between said seal elements and the pump chamber whereby heat may be transmitted to the liquid being pumped, said impeller having blades on its face adjacent the hub, positioned within said communication means, and effective, during a normal pumping operation, to reduce the pressures within said communication means.

9. A rotary liquid pump comprising a glass pump casing providing a pump chamber, said casing having a stuiiing box chamber, a glass impeller operable in the pump chamber and provided with a glass hub extending into the stufling box chamber,r in spaced relation to the wall thereof, seal elements between the hub and the stufng box chamberwall, at least one of said seal elements having 'a higher coeicientof heat transfer than glass, said impeller having a face adjacent and parallel to the wall of the casing,

' the 'liquidbeingipumped the impelleralso having .blades on said face, `within the 4.communication means, effective tto reduce the 'pressures in .said communication means.

.10. A rotary liquid 'pump comprising .9, glass pump casing "providing a pump chamber, said casing vhaving a stuffing box chamber, a glass impeller operable in the pump chamber and provided with .a .glass hub extending into the stufng .box chamber, in .spaced relation to the wall thereof, seal elements between the hub and the stufng `box `chamber wall, at yleast one of said -seal elements having ,a :higher coeflicient-of heat transfer'than glass, said impelle'r being perforated .adjacent its hub,'to establish communication between said seal elements and the pump chamber whereby heat may be transmitted to the liquid being pumped, blades .on the face adjacent the hub, .eective duringa normal pumping-operation to reduce the pressures in the region aboutsaidperforations.

11. A rotary liquid pump comprising va, glass .pump casing providing a pump chamber, said casing having .a stuffing `box chamber, a glass impeller operable in the pump chamber and provided with a glass hub extending into the stumng box chamber, inspaced relation `to the wall thereof seal=elements between .the hub and the-stuffing box chamber wall, at least one of said seal yelements havinga higher coeiiicient of heat transfer than glass, said :impeller being perforated adjacent its hub, to establish communication between said seal elements .and the pump chamber whereby heat Ymay be Vtransmitted to the liquid :being pumped, and effective during a normal pumping operation to reduce `the pressures in the region about said perforations.

12. In vaivitreous pumping unit having a vitreous pump v.casing and avitreous pumping means therein, both of which aresensitive to heat shock, stuflng box elements disposed betweenthe vitreous casing vand the kvitreous pumping means including frictional seal .surfaces consisting 4oi' glass vand carbon, heat insulating elements isolating thestufng box frictional surfaces from the vitreous pump casing and vitreous pumping means, and'means establishing a conduit between said frictional surfaces and the pump chamber whereby heat Amay be transmitted to the liquidV being pumped.

13. .A pump including a fixed wall defining part of the pump chamber and having a shaft opening, a -shaft passing through vsaid opening,

'and a stuiiing box between said wall and said shaft, including a pair of sealing members with respective annular surfaces in sealing ycontact blocking passage of .fluid between peripheral lopposite sides of said surfaces, said surfaces being i lin communication on one -peripheral'side with .the pump chamber and on .the other peripheral side with `a'n outlet under substantially reduced V.pressure, one of said sealing vmembers being Aaxially movable, and normally urged by working pressure from` the pump chamber .axially away from the other sealing member, a follower having a tubularproj ection embracing said `shaft extending into the .bore ofthe box in bearing relationship vwith respect to one of said sealing members, and spring means acting on said 'follower 'to urge said `movable -sealingmember axially .into sealing contact with the other sealing :member and Yagainst p ltheaction of said working pressure during normal l workingoperation of the pump, said spring means permitting said movable sealing member to be shifted axially away from the other sealing member `when the pressure on the peripheral side of :said surfaces in communication with the pump chamber becomes excessive, whereby release of the-excess pressure is effected lthrough the space between :said surfaces to the reduced pressure side .of vsaid surfaces.

14. A pump as described in claim 13, in which one of said sealing members is frangible, and in which .release of Vthe excess pressure is effected to prevent injury to said frangible member.

15. A pump as described in claim 13, in which substantial area, and an open passageway of substantial cross-sectional area is provided between Vand vbeing further provided with one peripheral side of said sealing surfaces and said outlet, whereupon krelease of excess pressure is effected almost instantaneously upon the pres- .sure spacing of said sealing members.

' i6. A pump including a pump chamber having a fixed wall and a tubular extension, a rotary shaft passing through said extension, and a stuifing .box between said extension and said shaft,

including a pair of seaiing members with respective annular surfaces in-sealing contact blocking passage of iiuid between peripherally opposite sides of said surfaces, said surfaces being in communication on their outer peripheral sides with the pump chamber and on their inner peripheral sides with an outlet under substantially reduced pressure, one of said sealing members being axially movable *l and normally urged by working pressure from the pump chamber axially away .from theother sealing member, a piston-like follower extending into said extension and around said shaft and engaging said axially movable sealing member, and coil spring means disposed outside of said extension and acting on said follower -to urge said movable sealing member axially into sealing contact with the other sealing member, and against the action of said working pressure, during Anormal working operations of the pump, .said spring meanspermitting saidI `movable sealing member to be shifted axially .away from the other sealing member when 'the pressure on the .outer peripheral sides of said surfaces becomes excessive, whereby the-excess pressure is effected through the space between said surfaces to the reduced pressure side of said surfaces.

11.- In a pumping unit, prising a pump casing and a pumping member, kboth made of a material `which is non-corrosive to the-action of the fluid pumped, but which is frangibly vsensitive to' heat shock, andl sealing means between said casing and said pumping means comprising a pair of sealing members, means for maintaining said sealing members in sealing rubbing contact during normal pumping operations, a heat insulating .element which is kdisposed vbetween one .of said sealing members v and said .casing and in contact with said casing a Aheat insulating eiement which is disposed between the other sealing .member and said pumprelease of the combination comi 19. In a pumping unit as described in claim 17,

in which spring means are provided for pressing said sealing members into sealing contact,

and both of said heat insulating members are of elastic material, whereby said sealing members are self-aligned into sealing contact.

20. A stuing box for sealing a pump opening, comprising a follower, guide posts passing through said follower, bushings axially slidable on said posts respectively and bearing axially inwardly on said follower, and coil springs encircling said guide posts respectively and bearing against corresponding bushings to spring-press said follower inwardly towards said opening into sealing position.

21. A stuiiing box as described in claim 20, in which each of said guide posts has a threaded portion carrying a nut on the inner side of the corresponding bushing adapted to be moved outwardly against said bushing to release the spring pressure on said follower.

22. A stufng box for a pump opening, comprising a follower, a plurality of coll springs spaced from the axis of said opening and arranged around said axis for urging said follower inwardly towards said opening into sealing position, and means operable upon a single manipulation forfreeing said follower from the action of all of said springs while maintaining said springs in stressed condition.

23. A stuffing box for a pump opening, comprising a follower, a plurality of coil springs urging said follower axially inwardly towards said opening into sealing position, and means for releasing said follower from the action of all of said springs simultaneously upon rotation of said follower. o

24. In a stuing box for a pump opening, the combination comprising a follower, a xed post, a coil spring encircling said post, a bushing slidable on said post and disposed between said follower and said spring, said spring axially urging said bushing in one axial direction against said follower to urge said follower in a corresponding direction inwardly towards said opening into sealing position. and means carried by said post and operable to move said bushing axially in the opposite direction against the action of said spring to release said follower from the action of said spring. j

25. In a stuing box for a pump opening,` the combination as described in claim 24, comprising releasable locking means between said follower and said bushing.,whereby said follower may be freed from the action of said spring, while maintaining said spring in stressed condition.

26. In a s tufiing box for a pump opening, the combination comprising a follower, a plurality of xed posts spaced from the axis of said opening,

coil springs encircling said posts respectively, bushings slidable on said posts respectively and disposed between said follower and said springs,V

said springs axially pressing said bushings in one axial direction against said follower to urge said follower in a corresponding direction inwardly towards said opening into sealing position, and nuts carried by said posts respectively andadapted to engage respective bushings and to move said bushings axially in the opposite-direction against the action'ofsaidsprings to release said follower from the action of sadsprings, while maintaining said springs in stressed condition, said follower having catch conformations adapted to be moved into catch position with respect to said bushings respectively upon rotation of said follower in one direction, and adapted to. be moved out of catch relationship with said bushings upon rotation thereofl in the-*opposite direction.

HAROLD E. ADAMS.

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